# 数据输入
sentence = input('请输入一个英文句子: ')
# 初始化变量
count_a = 0
# 统计单词数量
word_count = len(sentence.split())
letter_counts = {}
# 统计字母'a'的数量
for char in sentence:
    if char.lower() == 'a':
        count_a += 1
# 统计每个字母出现的次数
for char in sentence.lower():
    if char.isalpha():
        letter_counts[char] = letter_counts.get(char, 0) + 1
# 输出结果
print(f"字母 'a' 出现了{count_a}次")
print(f"句子中有{word_count}个单词")
print("每个字母出现的次数:")
for letter, count in letter_counts.items():
    print(f"{letter}出现了{count}次")